An off-duty Dallas police officer who shot and killed her neighbor after entering his own apartment had just finished a shift when she parked on the wrong floor of her building, according to an arrest warrant.

Officer Amber Guyger told investigators she used her electronic key to open the door to what she thought was her apartment, but was instead the entryway to the home of her upstairs neighbor Botham Shem Jean, according to the arrest affidavit obtained by BuzzFeed News.

Jean’s door had been slightly ajar before 10 p.m. Thursday when Guyger inserted her electronic key, the warrant states, so even though it did not unlock the door, the force of inserting the key pushed the door open into the darkened apartment.

The details in the arrest warrant from the Texas Rangers outline the alleged series of events that led to the deadly shooting between the white four-year veteran of the Dallas Police Department and her black neighbor.

The Texas Rangers are investigating the case, which could lead to manslaughter charges against Guyger.

Dallas District Attorney Faith Johnson told reporters Monday that her office would be presenting a case to a grand jury.

“We’re not going to be quick, we’re not going to jump the gun, and we're going to make sure we got all our ducks in a row,” Johnson said.

The officer-involved shooting has not only stoked anger over the shooting of an unarmed black man but has raised questions about the handling of the investigation, including Guyger’s arrest three days after the fatal shooting.

She turned herself in to the Kaufman County jail Sunday night and was released on a $300,000 bond, Kaufman County Sheriff's spokesperson Jolie Stewart said.

“This officer is absolutely getting special treatment. She’s being treated like a police officer in the United States when they commit a crime,” Lee Merritt, an attorney representing Jean’s family, said at a press conference. “It’s something that should not happen.”

According to the warrant, the off-duty officer had parked on the fourth floor of her building’s parking garage, not the third floor that leads directly into the corresponding floor of apartments.

The 30-year-old officer then walked down the fourth-floor hall into Jean’s unit, which sits directly above hers. According to authorities, Guyger said she believed she had walked in on a burglar in her own home.

“Believing she had encountered a burglar, which was described as a large silhouette across the room in her apartment; Guyger drew her firearm,” according to the arrest warrant.

Guyger also reported giving verbal commands to Jean in his own apartment before firing twice, authorities said. The warrant, however, does not list what those commands were or how much time passed between the time she issued them and when she fired her gun.

Ryan Tarinelli / AP

It wasn’t until after the shooting, and while she was on the phone with 911 dispatchers, that Guyger said she realized she had walked into the wrong unit, according to the warrant.

“Guyger turned on the interior lights while on the phone with 911,” the affidavit states. “Upon being asked where she was located by emergency dispatchers, Guyger returned to the front door to observe the address and discovered she was at the wrong apartment.”

Asked why Guyger was not arrested until three days after the shooting, Johnson said it was a decision made by the Texas Rangers, who have been asked to spearhead the investigation.

“I cannot dictate to the Texas Rangers their process,” Johnson said. “That was totally their call — that was totally their responsibility.”

But Merritt said authorities haven’t been able to explain to the family why Guyger was allowed to go free after the shooting, raising fears that the officer may be getting special treatment, a claim Johnson denied.

“Whether that was a responsibility of the DA’s office, or the Rangers, or the Dallas Police Department, it matters not to this family,” Merritt said. “What mattered was that this person was able to leave Botham’s home, return to her home, and not face any consequences for three days. That shows an extreme deference.”

Officials’ explanation that Guyger entered the wrong apartment has still left several questions in the family’s mind, Merritt said, including why the officer resorted to deadly force and whether she may have been somehow disoriented at the time.

During a press conference Monday evening, Merritt said two witnesses told him that shortly before hearing gunshots they heard a woman’s voice saying “let me in” and pounding on a door.

After the gunshots, the witness reported hearing a man’s voice saying, “Oh my God, why did you do that,” Merritt said, adding that he believes those were Jean’s last words.

Despite promises of transparency, Jean’s mother and attorneys representing his family also said the investigators, including the district attorney’s office, Dallas Police, and Texas Rangers, have not been forthcoming in filling in the gaps as to what happened Thursday night.

“I’m not satisfied that we have all the answers, and the number one answer that I want is what happened,” Jean’s mother, Allison Jean, said. “I have asked too many questions and I’ve been told that there are no answers yet.”

Salvador Hernandez is a reporter for BuzzFeed News and is based in Los Angeles.